Strong Electronic Interaction in High-Entropy Oxide Enhances Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High-entropy oxides (HEOs) are promising materials with diverse applications.
• A universal preparation method for HEOs is currently lacking, hindering their study and use.

Purpose of the Study:

• To develop a universal spray pyrolysis method for preparing various HEOs.
• To investigate the electrocatalytic performance of HEOs for the oxygen evolution reaction (OER).

Main Methods:

• Spray pyrolysis was employed to synthesize a range of HEOs.
• Electrocatalytic performance for OER was evaluated using techniques like overpotential and Tafel slope measurements.

Main Results:

• FeCoNiMoWO HEO demonstrated superior OER performance with an overpotential of 281 mV at 10 mA cm⁻² and a Tafel slope of 34.5 mV dec⁻¹.
• High entropy in HEOs enhanced interactions and created oxygen vacancies (OVs), contributing to improved catalytic activity.

Conclusions:

• Spray pyrolysis offers a universal approach for HEO synthesis.
• This study deepens the understanding of OER catalytic mechanisms in HEOs, highlighting the role of high entropy and oxygen vacancies.